We describe 2 human immunodeficiency virus-infected patients who developed hypertension and severe neurological abnormalities while receiving successful antiretroviral therapy. Neuroimaging findings were characteristic of reversible posterior leukoencephalopathy syndrome, a brain-capillary leak syndrome with hypertension and endothelial damage. We discuss the role of antiretroviral therapy-associated metabolic alterations in endothelial damage, hypertension, and reversible posterior leukoencephalopathy syndrome.